public class Subsequence extends SystemFunctionCall implements Callable
operationargumentEFFECTIVE_BOOLEAN_VALUE, EVALUATE_METHOD, EVENT_FEED_METHOD, INHERITED_CONTEXT, INSPECTION_CONTEXT, ITEM_FEED_METHOD, ITERATE_METHOD, locationId, MAX_SEQUENCE_LENGTH, MAX_STRING_LENGTH, NAVIGATION_CONTEXT, NODE_VALUE_CONTEXT, PROCESS_METHOD, PUSH_SELECTION, staticProperties, UNBOUNDED_LOWER, UNBOUNDED_UPPER, W3C_CONSUMING, W3C_FREE_RANGING, W3C_GROUP_CONSUMING, W3C_MOTIONLESS, WATCH_METHOD| Constructor and Description |
|---|
Subsequence() |
| Modifier and Type | Method and Description |
|---|---|
Sequence |
call(XPathContext context,
Sequence[] arguments)
Call the Callable.
|
int |
computeCardinality()
Determine the cardinality of the function.
|
int |
computeSpecialProperties()
Get the static properties of this expression (other than its type).
|
ItemType |
getItemType(TypeHierarchy th)
Determine the data type of the items in the sequence
|
SequenceIterator<? extends Item> |
iterate(XPathContext context)
Evaluate the function to return an iteration of selected nodes.
|
Expression |
optimize(ExpressionVisitor visitor,
ExpressionVisitor.ContextItemType contextItemType)
Perform optimisation of an expression and its subexpressions.
|
static SequenceIterator |
subSequence(SequenceIterator seq,
NumericValue startVal,
NumericValue lengthVal,
XPathContext context) |
Pattern |
toStreamingPattern(Configuration config,
List<String> reasonForFailure)
Convert this expression to a streaming pattern (a pattern used internally to match nodes during
push processing of an event stream)
|
addContextDocumentArgument, addDocToPathMap, bindStaticContext, checkArguments, copy, equalOrNull, equals, getContextNode, getConvertingCallable, getDefaultArgumentNode, getDetails, getErrorCodeForTypeErrors, getFunctionItemType, getImplementationMethod, getOperation, getRequiredType, iterateSubExpressionInfo, makeSystemFunction, setDetails, useContextItemAsDefaultaddExternalFunctionCallToPathMap, checkArgumentCount, explain, getArguments, getDisplayName, getExpressionName, getFunctionName, getNumberOfArguments, hashCode, iterateSubExpressions, preEvaluate, promote, replaceSubExpression, setArguments, setFunctionName, simplify, simplifyArguments, toString, typeCheckaddToPathMap, adoptChildExpression, checkForUpdatingSubexpressions, checkPermittedContents, computeDependencies, computeStaticProperties, doPromotion, dynamicError, effectiveBooleanValue, evaluateAsString, evaluateItem, evaluatePendingUpdates, explain, getCardinality, getColumnNumber, getColumnNumber, getConstructType, getContainer, getDependencies, getEvaluationMethod, getExecutable, getExpressionCompiler, getHostLanguage, getIntegerBounds, getIntrinsicDependencies, getLineNumber, getLineNumber, getLocationId, getLocationProvider, getObjectName, getProperties, getProperty, getPublicId, getSlotsUsed, getSpecialProperties, getStreamability, getStreamingAdjunct, getSystemId, getSystemId, hasVariableBinding, implementsStaticTypeCheck, isSubtreeExpression, isUpdatingExpression, isVacuousExpression, iterateEvents, markTailFunctionCalls, process, resetLocalStaticProperties, setContainer, setEvaluationMethod, setFiltered, setFlattened, setLocationId, staticTypeCheck, suppressValidation, toPattern, typeErrorpublic ItemType getItemType(TypeHierarchy th)
getItemType in class SystemFunctionCallth - the type hierarchy cachepublic int computeSpecialProperties()
computeSpecialProperties in class SystemFunctionCallpublic int computeCardinality()
computeCardinality in class SystemFunctionCallStaticProperty.ALLOWS_ZERO_OR_ONE,
StaticProperty.EXACTLY_ONE, StaticProperty.ALLOWS_ONE_OR_MORE,
StaticProperty.ALLOWS_ZERO_OR_MOREpublic Expression optimize(ExpressionVisitor visitor, ExpressionVisitor.ContextItemType contextItemType) throws XPathException
This method is called after all references to functions and variables have been resolved to the declaration of the function or variable, and after all type checking has been done.
optimize in class SystemFunctionCallvisitor - an expression visitorcontextItemType - the static type of "." at the point where this expression is invoked.
The parameter is set to null if it is known statically that the context item will be undefined.
If the type of the context item is not known statically, the argument is set to
Type.ITEM_TYPEXPathException - if an error is discovered during this phase
(typically a type error)public Pattern toStreamingPattern(Configuration config, List<String> reasonForFailure)
toStreamingPattern in class Expressionconfig - the Saxon configurationreasonForFailure - a list which will be populated with messages giving reasons why the
expression cannot be convertedpublic SequenceIterator<? extends Item> iterate(XPathContext context) throws XPathException
iterate in class Expressioncontext - supplies the context for evaluationXPathException - if any dynamic error occurs evaluating the
expressionpublic Sequence call(XPathContext context, Sequence[] arguments) throws XPathException
Callablecall in interface Callablecontext - the dynamic evaluation contextarguments - the values of the arguments, supplied as Sequences.
Generally it is advisable, if calling iterate() to process a supplied sequence, to
call it only once; if the value is required more than once, it should first be converted
to a GroundedValue by calling the utility methd
SequenceTool.toGroundedValue().
If the expected value is a single item, the item should be obtained by calling
Sequence.head(): it cannot be assumed that the item will be passed as an instance of
Item or AtomicValue.
It is the caller's responsibility to perform any type conversions required to convert arguments to the type expected by the callee. An exception is where this Callable is explicitly an argument-converting wrapper around the original Callable.
XPathException - if a dynamic error occurs during the evaluation of the expressionpublic static SequenceIterator subSequence(SequenceIterator seq, NumericValue startVal, NumericValue lengthVal, XPathContext context) throws XPathException
XPathExceptionCopyright (c) 2004-2013 Saxonica Limited. All rights reserved.